Chair iron

ABSTRACT

434,060. Tilting seats. BASSICK CO., 38, Austin Street, Bridgeport, Connecticut, U.S.A. Oct. 29, 1934, No. 30957. Convention date, Oct. 31, 1933. [Class 52 (ii)] In a tilting seat, a tiltable seat support 10 is mounted upon a bracket 11 by means of relatively rotatable cylindrical elements 14, 15 with an interposed cylinder 16 of highly compressed rubber bonded to the elements 14, 15. The inner element 15 is secured to the side members of the support 10, and the outer element 14 is rotatably mounted in the side walls of a cut-away part of the bracket 11, but is secured by a set-screw 28 to a torsion adjustment lever 26 provided with a screw 30 which bears against a part 23 of the bracket 11 to adjust the initial torsion of the rubber cylinder 16.

July 16, 1935. w F, HEROLD 2,008,209

CHAIR IRON Filed oet. 31, 1955 2 sheets-sheet 1 4 EQJ. V5

/0 2f 24,917 l/f/ 27 IN VEN TOR.

NHLTBH FHERULD.

w. F. HEROLD 2.008,209

CHAIR IRON July 16, 1935.

2 Sheets-Sheet 2 Filed Oct. 3l, 1933 ATTORNEY.

Patented July 16, 1935 UNITED STATES `2,ooszo9 PATENT OFFICE CHAIR IRON Application October 31,

13 Claims.

The present invention relates to chair irons, particularly for use with tiltable chair seats, and usually mounted for swiveling movement upon a base support.

Heretofore chair irons have for the most part employed coil springs for supporting the tilting movement and various means have been devised for mounting the springs and regulating the tension, but in all of these the relatively movable metal parts were in contact and under pressur'ej, of the springs so that during relative movement/ there was considerable surface friction with the result that the tilting action was irregular and the parts would creak and squeak. They furthermore required frequent lubrication, and this was not only very inconvenient and objectionable, because of the inaccessibility of the mechanism and the likelihood of soiling the hands and clothing, but the lubricated structure became a trap for picking up dirt and dust.

An object of the present invention is to provide a chair iron in which the tilting action takes place in a, hinge joint of rubber or other suitable resilient material, the rubber preferably being in the form of a cylinder disposed under permanent pressure and tension between two coaxially movable members disposed one within the other and to each of which the rubber is in effect bonded, the relative movement between these members being resiliently supported by the torsional strain set up in the compressed rubber.

A further object is to provide a chair iron construction providing an entirely resilient rubber cushioned full floating support in all directions and an easy cushioned action. Another object is to provide a chair iron which will be noiseless in operation, will not deteriorate to any appreciable extent even after long and excessive use, and will require no lubrication. A further object is to provide a chair iron which may be conveniently and effectively adjusted to obtain the desired tension for the particular requirements of the user of the chair.

With the above and other objects in view emr bodiments of the invention are shown in the accompanying drawings, and these embodiments will be hereinafter more fully described with reference thereto, and the invention will be finally pointed out in the claims.

In the drawings:

Fig. 1 is a side elevation of a chair iron, embodying the present invention.

Fig. 2 is a plan View of the same, portions of the spider-arms being broken away.

Fig. 3 is a front view, the spider arms being shown in section, taken along the line 3 3 of Fig. 1.

Fig. 4 is a section, taken along the line 4-4 of Fig. 2.

1933, Serial No. 695,989

Fig. 5 is a section, taken along the line 5-5 of Fig. 2.

Fig. 6 is a perspective view of the joint element employed.

Fig. 7 is a side elevation of a modified form of chair iron, embodying the invention, portions of the spider arms being broken away.

Fig. 8 is a plan view of the same.

Fig. 9 is a front view, the spider arms being shown in section, taken along the line 9--9 of Fis. 7.

Fig. 10 is a section taken along the line Ill- Ill of Fig. 8.

Fig. 11 is a. section taken along the line II-II of Fig. 8.

Fig. 12 is a perspective view of the joint element employed.

Similar reference characters indicate corresponding parts throughout the several gures of the drawings.

Referring to the drawings and more particularly to Figs. 1 to 6 thereof, the chair iron according to the illustrated exemplary embodiment of the invention shown therein comprises a pair of angular cross-section spider arms Ill-I 0 adapted to be screwed to the under side of the chair seat in the usual manner, and mounted for tilting movement upon a bracket II secured by a set screw I2 to the upper end of the vertically disposed spindle I3 the tiltable mounting of the spider arms being eiected by securing one member of the joint element to the bracket and the other member to the spider arms, the resilient rubber support being disposed between these members, as will presently more fully appear.

The joint element comprises an outer tubular member I4, an inner tubular member I5, and a cylindrical body of rubber I6 between them, this rubber body being highly compressed and confined between the members I4 and I5 and being in effect bonded to their surfaces, so that upon relative rotary movement between the members I4 and I5 the rubber body is put under torsional strain. In practice the rubber body is bonded to the inner member l5, as by vulcanization, and is then forced into the outer member I4 under great pressure, its diameter prior to insertion in the member I4 being considerably greater than the interior diameter of the member I4, so that the rubber is thus highly compressed and is in effect bonded to the inner surface of the member I4 by the great surface friction set up between them under compression. The ends of the rubber profject beyond the ends of the outer member I5, as at ISB-I6, and the ends of the inner member I4 project beyond the rubber body and are shoulydered and ilatted to produce key lugs Il-II for locking the inner member to the spider arms. For this purpose the spider arms are each provided with an aperture I8 and outwardly extending cut-outs I9-I9 for receiving the lugs I1, a tie bolt 20 being engaged through the bore of the member I5 and having its threaded ends extended through the apertures I8 and secured by nuts 2I2I, this assembly rigidly connecting the spider arms to the inner member I5 and providing a supporting spacer or strut between the arms.

The bracket I I is provided with a forwardly projecting yoke portion 22, having a transverse connecting bridge portion 23 at its forward end, against which the upper portions of the spider arms I0 rest in the normal non-tilted position of the chair seat. The tilting axis of the joint is disposed within the yoke portion forwardly of the vertical swivel axis of the spindle I3, and the upper surface of the bracket is inclined rearwardly and downwardly, as at 24, tangential'ly of the tilting arc of the spider arms to form a limit stop to the tilting action, as shown in dot-and-dash lines in Fig. 5.

The yoke portion 23 of the bracket is provided in each side with cylindrical bearing openings 25-25 in which the end portions of the outer joint member I4 are engaged for rotary adjustment movement, as will presently more fully appear. Within the space between the sides of the yoke portion a tension adjustment lever 26 is disposed and projects beneath the bridge portion 23, its collar portion 21 being engaged about the intermediate portion of the outer joint member I4 and secured thereto by a set-screw 28, the member I4 having a hole 29 therein in which the end of the set-screw lockingly engages. An adjusting screw 3D having a hand-wheel or nut 3I at its end is engaged in a threaded opening 32 in the end of the lever 2S and bears at its upper end upon the under surface of the bridge portion 23.

It will be obvious that by adjusting the screw 39 the outer joint member I4 is rotated with respect to the bracket I I and the inner joint member I5, and through the torsional strain imposed on the rubber i6 any desired initial tension may be set up in the latter, the greater the initial tension the more force required to tilt the chair seat.

Y The spindle i3 passes down through the chair base 33 and is mounted for swiveling movement and vertical adjustment in respect thereto. For this purpose a collar 34 is provided on the spindle through which the spindle is free to move vertically, and within a rearwardly extending portion of this collan a vertical adjusting screw 35 is swivelly secured by a cotter pin 36, a hand-wheel or nut 31 being secured upon the screw above the collar and the screw engaging a vertical threaded passage 38 in the bracket II.

A skirt portion 39 of the collar rests upon the upper iianged end 40 of a tubular bushing 4I secured in the chair base, a bearing washer 42 being interposed between the iiange and the skirt and upon which the collar is free to swivel. A set-screw 43 in the skirt has its inner end disposed beneath the ange 40 and retains the collar and spindle against vertical displacement while permitting free swiveling action. Turning of the screw 35 adjusts the height of the chair seat and connected parts relatively to the collar 34 and chair base 33.

The chair iron, according to my invention gives full iioating resilient support to the chair seat by the interposing of the compressed tensioned rubber I6 between. the outer and inner joint members I4 and I5, and by the disposition of the rubber ends I6a-I6` between the sides of the spider-arms and the outer member I4, so that in sitting in the chair there is a distinct cushioning effect. vWhen the seat is tilted the building up of tension in the rubber, while permittingan easy tilting action, preventssudden or hard tilting to the limit position.

As no lubrication is required the device will remain in perfect working order indenitely without attention. It has been found that the high compression rubber will not deteriorate, even after very long and excessive use, and as only the surfaces of the ends IBL-I6a are exposed to air or moisture deterioration due to these causes is negligible.

In Figs. 7 to 12 I have shown a modiiied embodiment of the invention inwhich adjustment of the tension is effected through rotation of the outer joint member relative to the tilting spider arms, rather than relatively to the non-tilting supporting bracket as in the rstform.

The spider-arms 5050 are riveted to a. spreader having a transverse connecting top portion 5I and depending side flanges 5252. The bracket 53, which is secured by the set screw I2 to the spindle I3 in asimilar manner to the first embodiment, is provided with a cylindrical bore 54 adapted to receive the joint element, and at its forward end is provided with a rib 55 against which the under side of the spreader engages in the non-tilted position'. The upper surface is provided in tangential relation to the tilting arc of the spreader with a downwardly inclined surface 56 adapted to limit the tilting movement through abutment of the spreader therewith, as shown in dot-and-dash linesin Fig. 11.

The joint element is substantially similar to that of the first embodiment, comprising an outer cylindrical tubular member 51, an inner cylindrical spindle member 58, and a tubular rubber member 59, having its ends 599-59al extended beyond the member 51, While the member 58 extends beyond the rubber member. The outer member 51 is secured Within the bore 54 of the bracket 53 by means of a set screw 60. 'I'he ends of the spindle member 58 are provided with reduced extensions, shouldered and squared, as at 6 I-6I adjacent the ends of the rubber member, and shouldered and cylindrical at the extremities, as at 62--62. The spindle ends 62--62 are engaged for rotary adjustment in bearing notches 63-63 in the respective sides of the side flanges 52 of the spreader, being retained therein by pinching up the metal at the edges of the notches forwardly of the spindle ends, as at 64.

The square spindle portions BI--BI are engaged in rectangular notches 65-65 at the inner ends of the sides 66-66 of a tension adjusting yoke member, being retained therein by pinching up the metal at the edges of the notches rearwardly of the portions fil-6I, as at 61.

The forward transverse connecting portion 68 of the yoke member is provided at its upper edge with an inwardly bent iiange 69, having an aperture 1I) therein through which the shank of an adjustment screw 1I is engaged, the upper end of this screw being extended through an aperture 12 in the top 5I of the spreader member, and being rockably connected thereto by means of a cross-pin 13 seated in arecess 14 pressed in the top 5I at each side of the aperture 12. Upon the lower threaded end of the screw there is engaged a hand-wheel or nut 15 pressing upon a spacer bushing 16 engaged about the screw between the hand-wheel and the flange 69. Adjustment is eiected by turning the hand-wheel causing the yoke member to swing relatively to the spreader member, the spindle member 58 of the joint element being thereby rotated to produce the desired initial torsional strain in the rubber 59 between the spindle member 59 and the outer cylindrical member 51.

The swivel mounting of the spindle I3 and the vertical adjustment means are the same as those of the first embodiment so that a further detail description of these is unnecessary.

I have illustrated and described preferred and satisfactory embodiments of my invention, but it will be obvious that changes may be made therein, within the spirit and scope thereof, as dened in the appended claims.

Having thus described my invention what I claim and desire to secure by Letters Patent iszl. The combination in a chair including a base member and a tilting member, of a torsional joint carried by said base member supporting said tilting member and permitting limited tilting movement about a horizontal axis comprising a pair of relatively rotatable elements axially coincident with said horizontal tilting axis and secured to said respective members, and a torsion element of elastic material disposed between said relatively rotatable elements and joined to each of said elements against rotation with respect thereto, said material being circumferentially continuous between its jointures with said elements whereby relative turning movement between said elements imparts direotionally uniform distortion and tension to the entire circumferential body of said elastic material.

2. The combination in a chair including a base member and a tilting member, of a torsional joint carried by said base member supporting said tilting member and permitting limited tilting movement about a horizontal axis comprising a pair of relatively rotatable elements axially coindident with said horizontal tilting axis and secured to said respective members, and a torsion element of elastic material compressed and conned between said relatively rotatable elements and joined to each of said elements against rotation with respect thereto, said material being circumferentially continuous between its jointures with said elements whereby relative turning movement between said elements imparts directionally uniform distortion and tension to the entire circumferential body of said elastic material, the compression and tension of said material being such that the variation of tension is substantially proportionate to the variation of the pressure moment as the tilting member is tilted whereby the pressure is in a state of approximately stable equilibrium at any point of tilt.

3. The combination in a chair including a base member and a tilting member, of a torsional joint carried by said base member supporting said tilting member and permitting limited tilting movement about a horizontal axis comprising a pair of relatively rotatable elements axially coincident with said horizontal tilting axis and secured to said respective members, and a torsion element of elastic material disposed between said relatively rotatable elements and joined to each of said elements against rotation with respect thereto, said material beingcircumferentially continuous between its jointures with said elements whereby relative turning movement between said elements imparts directionally uniform distortion and tension to the entire circumferential body of said elastic material, stop means coacting between said base member and said tilting member to limit the forward tilting movement, the relation between said relatively rotatable elements being such that an initial distortion and tension is set up in said elastic material in a direction opposed to the direction of distortion as the tilting member is tilted rearwardly and whereby said tilting member is normally pressed forwardly.

4. The combination in a chair including a base member and tilting member, of a torsional joint carried by said base member supporting said tilting member and permitting limited tilting movement about a horzontal axis comprising a pair of relatively rotatable elements axially coincident with said horizontal tilting axis and secured to said respective members, 4and aA torsion element of elastic material disposed between said relatively rotatable elements and joined to each of said elements against rotation with respect thereto, said material being circumferentially continuous between its jointures with said elements whereby relative turning movement between said elements imparts directionally uniform distortion and tension to the entire circumferential body of said elastic material, a stop carried by said base member to limit the forward tilting movement, another stop carried by said base member to limit the rearward tilting movement to an angular movement less than 90' degrees.

5. The combination in a chair including a base member and a tilting member, of a. torsional joint carried by said base member supporting said tilting member and permitting limited tilting movement about a horizontal axis comprising a pair of relatively rotatable elements axially coincident with said horizontal tilting axis and secured to said respective members, and a. torsion element of elastic material disposed between said relatively rotatable elements and joined to each of said elements against rotation with respect thereto, said material being circumferentially continuous between its jointures with said elements whereby relative turning movement between said elements imparts directionally uniform distortion and tension to the entire circumferential body of said elastic material, stop means coacting between said base member and said tilting member to limit the forward tilting movement, adjustment means for imparting varying degrees of relative rotary movement between said pair of relatively rotatable elements in a direction opposed to the relative movement as said tilting member is tilted rearwardly whereby a predetermined initial distortion and tension is set up in said elastic material to .normally press said tilting member forwardly.

6. The combination in a chair including a base member and a tilting member, of a torsional joint carried by said base member supporting said tilting member and permitting limited tilting movement about a horizontal axis comprising a pair of relatively rotatable elements axially coincident with said horizontal tilting axis and secured to said respective members, and a torsion element of elastic material compressed and confined between said relatively rotatable elements and joined to each of said elements against rotation with respect thereto, said material being circumferentially continuous between its jointures with said elements whereby relative turning movement between said elements imparts directionally uniform distortion and tension to the entire circumferential body of said elastic material, said elastic material being held under such high compression between said relatively rotatable elements that radial displacement is"substantially prevented, the compression and tension of said material being such that the variation of tension is substantially proportionate to the variation of the pres- 5 sure moment as the tilting member is tilted whereby the pressure is in a state of approximately stable equilibrium at any point of tilt.

7. The combination in a chair including a base member and a tilting member, of a torsional joint carried by said base member supporting said tilting member and permitting limited tilting movement about a horizontal axis comprising an inner element axially coincident with said horizontal tilting axis and secured to one of said members, an outer socket element spaced about said inner element and' secured to the other of said members, and a torsion element of elastic material compressed and conned between said inner element and said socket element, and joined to each of said elements against rotation with respect thereto.

8. The combination in a chair including a base member and a tilting member, of a torsional joint carried by said base member supporting said tilting member and permitting limited tilting movement about a horizontal axis comprising an inner element axially coincident with said horizontal tilting axis and secured to one of said members, an outer socket element concentricaliy spaced about said inner element and secured to the other of said members, and a cylindrical sleeve element of circumferentially continuous elastic material disposed between said inner element and said socket element and joined to each of said elements uniformly about their respective outer and inner circumferential surfaces against rotation with respect thereto whereby relative turning movement between said-elements imparts directionally uniform distortion and tension to the entire circumferential body of said elastic material.

9. The combination in a chair including a base member and a tilting member, of a torsional joint carried by said base member supporting said tilting memberand permitting limited tilting movement about a horizontal axis comprising an inner element axially coincident with said horizontal tilting axis and secured to said tilting member, an outer socket element concentrically spaced about said inner element and secured to said base member, and a cylindrical sleeve element of elastic material disposed between said inner element and said socket element, and joined to each of said elements uniformly about their respective outer and inner circumferential surfaces against rotation with respect thereto whereby relative turning movement between said elements imparts directionally uniform distortion and tension to the entire circumerential -body of said elastic material.

10.F`The combination in a chair including a base member and a tilting member, of a torsional joint carried by said base member supporting said tilting member and permitting limited tilting movement about a horizontal axis comprising an inner element axially coincident with said horizontal tilting axis and secured to one of said members, an outer socket element spaced about said inner element and secured to the other of said members, and a sleeve element of elastic material disposed between said inner element and said socket element, said elastic material being held under such high compressio-n between said inner and outer elements that radial displacement is substantially prevented, andsaid material being joined to them about their respective outer and inner circumferential surfaces against rotation with respect thereto whereby relative turning movement between said members distorts and tensions the entire circumferential body of said elastic material and the elastic structure thereof is increasingly tensioned as said elements are relatively moved through the increasing tilt of said tilting member, the compression and tension of said material being such that the variation of tension is substantially proportionate t0 the variation of the pressure moment as the tilting member is tilted whereby the pressure is in a state of approximately stable equilibrium at any point of tilt. v,

ll. The combination in a chair including a base member and a tilting member, of a torsional joint carried by said base member supporting said tilting member and permitting limited tilting movement about a horizontal axis comprising an axially elongated inner element axially coincident with said horizontal tilting axis, and secured to one of said members, an axially elongated outer socket element concentrically spaced about said inner element and secured to the other of said members, and a sleeve element of radially comthem about their respective outer and inner cirt cumferential surfaces against rotation with respect thereto, whereby relative turning movement 'between said members distorts and tensions the entire circumferential body of said elastic material and the elastic structure thereof is increasingly tensioned as said elements are relatively moved through the increasing tiltof said tilting member, the compression and tension of said material being such that the variation of tension is substantially proportionate to the variation of the pressure moment as the tilting member is tilted whereby the pressure is in a state of approximately stable equilibrium at any point of tilt.

12. A seat having a seat member, a support for said seat member, and means mounting said scat member upon said support for tilting movement about a horizontal axis, said mounting means comprising cylindrical bearing elements on said support and on said seat member respectively and respectively rigid with said support and with said seat member, said bearing elements being arranged one within the other in coaxial relation and a rubber sleeve between said bearing elements interiorly bonded to the inner bearing element and exteriorly bonded to the outer bearing element.

13. In a chair, a tiltable member, a support for said tiltable member supporting said tiltable member for tilting movement about a horizontal axis, resilient means resisting tilting movement of said tiltable member comprising a pair of bearing elements one within the other, and a rubber sleeve between said bearing elements interiorly bonded to the inner bearing element and exterioriy bonded to the outer bearing element, one'of said bearing elements being rigidly connected with said tiltable member, and means rigidly connected to said other bearing element and in operative engagement with said support, 

